Reamer for oil or like wells.



No. 668,340.- Patented Feb. I9, I90].

W. PLUTTS. REAMER FUR OIL 0 R LIKE WELLS.

' (Hp Model.)

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WILLIAM PLOTTS, OF MCDONALD, PENNSYLVANIA.

REAMER FOR OIL OR LIKE WELLS.

SPECIFICATION forming part of Letters Patent N 0. 668,340, datedFebruary 19, 1 901.

Application filed May 6,1897. berial No. 635,351. (No model.)

T0 at whmn it may concern.-

Be it known that I, WILLIAM PLOTTS, a resident of McDonald, in the county of Washington and State of Pennsylvania, have invented a new anduseful Improvement in Reamers for Oil and Like Wells; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof.

Myinvention relates to reamers for oil and like wells.

The invention has reference more particularly to that class of reamersgenerally known as under reaniers, in which a cutter is employed whichnormally projects out beyond the body of the cutter, but which whenpassing through the casing is withdrawn, so as not to interfere with thepassage of the reamer through the same. The difficulty heretofore in theuse of this class of under reamers has been the liability of thebreakingor bending of the pin on which the cutter is mounted when said cutter issubjected to the severe strains which they have to bear in the cuttingof the rock. If the pin breaks and the cutter is detached and becomeslodged in the well, it may prevent the further drilling of the well.

The object of my invention is to provide a reamer with the cutting-knifeso securedand protected against strains as to obviate the difficultyhereinbefore referred to.

To this end my invention comprises, gen- 7 erally stated, a reamerhaving formed in the body portion thereof a seat or recess, a cuttermounted on a pin in said seat, the inner end of said cutter abuttingagainst the solid body of the reamer at the inner face of said seat andthe outer end extending normally beyond said body, (in a horizontalposition,) and spring mechanism for retaining said outter in thisposition.

To enable others skilled in the art to make and use my invention, I willdescribe the same more fully, referring to the accompanying drawings, inwhich Figure 1 is a View of my improved reamer in use in a Well. Fig. 2is a view showing the same passing through the casing. Fig. 3 is anenlarged longitudinal section of the reamer removed from the well.

Like letters of reference indicate like parts in each view.

The letter a represents the body of the reamer,having the ordinarythreaded connection a at its upper end and the threaded seat a at itslower end, with which the bit b en gages.

A seat or recess 0 is formed in the body a at a suitable point therein.This seat 0 is preferably formed, as illustrated, with the straightupper face 0', the curved rear face 0 and the inclined face 0 Mounted onthe pin 01 is the cutter c, said cutter having the straight upper edgee, the curved rear edge e the lower edge 6 with the recess 6 formedtherein, and the outer cutting edge 6 When the cutter e is mounted onthe pin (1 and held in its normal position, the upper edge 6 will be incontact with the upper face 0 of the seat 0, the curved rear edge 6 willabut against the curved rear face 0 while the cutting edge e will extendbeyond the body of the reamer.

In order to retain the cutter c in its normal position for cutting, arod f, movable vertically in a seat g formed for it in the body a, hasits upper end forced into contact with the lower edge e of the cutter eby means of the spring h. This spring h fits in an enlarged portion g ofthe seat 9 and presses against a headf on said rod f, said spring beinginterposed between said head f and the bottom of the seat g, whichconsists of the plug 9 By the above construction the seat g is only ofsufficient diameter to permit of the rodf moving freely therein, so thatI do not weaken the body of the reamer so much as where the springencircles the rod and necessitates a seat of the same size as theenlarged portion gfor its entire length.

The operation of my improved reamer is as follows: When the reamer isbeing lowered through the casing, the cutter e will have its outer orcutting edge 6 moving in contact with the casing, and accordingly thecutter e will assume the position shown in Fig. 2. In this case thepressure brought to bear upon the cutter to lower same will also lowerthe rod f until the lower edge e of said cutter comes in contact withthe inclined face 0 of the seat 0, whereupon the upper end of the rod fwill enter the recess 6 in the cutter e. In this manner the reamer islowered until it gets beyond the casing, as sho am in Fig. l,

whereupon the spring h forces up the rod 1 and the cutter e resumes itsnormal position Within the seat 0. The cutter then has its cutting edge6 extending beyond the body of the reamer, in position to cut the rockbelow the lower end of the casing to permit of said casing beinglowered. The reamer is raised and lowered in the ordinary manner ofdrilling, said reamer being also turned at each stroke. The cutter thuscuts under the casing in the manner illustrated.

The cutter may be used in connection with the drill-bit, as shown, or itmay be used independently, if desired.-

By having the cutter supported in the manner described, with its rearedge e? backed up by the solid body of the 'reamer, any tendency towardinward movement on the part of the cutter is resisted, so that there ispractically no strain on the pin (1. This prevents the bending orbreaking of the pin d and the consequent displacement of the cutter orits complete detachment from the reamer. I have found by experience thatthe severest strains brought uponthe cutter are those lateral orhorizontal strains which come from Consequently by my construction thecutter is braced and backed up in such a manner as to withstand thesethe walls of the well.

strains without injury.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a reamer for oil and like wells, the combination with a solid bodyportion having a recess formed therein and a pinprojecting through therear portion of the recess, said recess adjacent to the pin beingconcentric therewith, of a cutter pivotally mounted on said pinandhaving a rear end that conforms to and closely fits the portion of therecess that is concentric with the pin, and a spring for holding saidcutter normally up in a horizontal position, substantially as set forth.

2. In a reauier for oil and like wells, the combination with a solidbody portion having a recess formed therein and a pin projecting throughsaid recess, adjacent to the rear end thereof, the upper side of saidrecess being substantially perpendicular to the axis of the reamer-bodyand the rear portion being concentric with the pin, of a cutter having arear end that closely fits the rear end of the recess, and a top edgethat fits the upper side of the recess when in working position, and aspring for holding said cutter normally in a horizontal position,substantially as set, forth.

3. In a reamer for oil and like wells, the combination with a solid bodyportion having a recess therein and a pin projecting through said recessadjacent to the rear end thereof, said rear end being concentric withthe pin, of a cutter pivotally mounted on said pin and having a rear endthat conforms to and closely fits the rear end of the recess, averticallymovable rod below said-cutter, and a spring adapted to forcesaid rod into engagement with said-cutter, substantially as set forth.

In testimony whereof I, the said WILLIAM PLOTTS, have hereunto set myhand.

WILLIAM PLOTTS.

Witnesses:

ROBT. D. TOTTEN, ROBERT C. TOTTEN.

